1 /* 2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP 26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP 27 28 #include "classfile/classLoader.hpp" 29 #include "jvmci/systemDictionary_jvmci.hpp" 30 #include "oops/objArrayOop.hpp" 31 #include "oops/symbol.hpp" 32 #include "runtime/java.hpp" 33 #include "runtime/reflectionUtils.hpp" 34 #include "runtime/signature.hpp" 35 #include "utilities/hashtable.hpp" 36 37 // The dictionary in each ClassLoaderData stores all loaded classes, either 38 // initiatied by its class loader or defined by its class loader: 39 // 40 // class loader -> ClassLoaderData -> [class, protection domain set] 41 // 42 // Classes are loaded lazily. The default VM class loader is 43 // represented as NULL. 44 45 // The underlying data structure is an open hash table (Dictionary) per 46 // ClassLoaderData with a fixed number of buckets. During loading the 47 // class loader object is locked, (for the VM loader a private lock object is used). 48 // The global SystemDictionary_lock is held for all additions into the ClassLoaderData 49 // dictionaries. TODO: fix lock granularity so that class loading can 50 // be done concurrently, but only by different loaders. 51 // 52 // During loading a placeholder (name, loader) is temporarily placed in 53 // a side data structure, and is used to detect ClassCircularityErrors 54 // and to perform verification during GC. A GC can occur in the midst 55 // of class loading, as we call out to Java, have to take locks, etc. 56 // 57 // When class loading is finished, a new entry is added to the dictionary 58 // of the class loader and the placeholder is removed. Note that the protection 59 // domain field of the dictionary entry has not yet been filled in when 60 // the "real" dictionary entry is created. 61 // 62 // Clients of this class who are interested in finding if a class has 63 // been completely loaded -- not classes in the process of being loaded -- 64 // can read the dictionary unlocked. This is safe because 65 // - entries are only deleted at safepoints 66 // - readers cannot come to a safepoint while actively examining 67 // an entry (an entry cannot be deleted from under a reader) 68 // - entries must be fully formed before they are available to concurrent 69 // readers (we must ensure write ordering) 70 // 71 // Note that placeholders are deleted at any time, as they are removed 72 // when a class is completely loaded. Therefore, readers as well as writers 73 // of placeholders must hold the SystemDictionary_lock. 74 // 75 76 class ClassFileStream; 77 class Dictionary; 78 class PlaceholderTable; 79 class LoaderConstraintTable; 80 template <MEMFLAGS F> class HashtableBucket; 81 class ResolutionErrorTable; 82 class SymbolPropertyTable; 83 class ProtectionDomainCacheTable; 84 class ProtectionDomainCacheEntry; 85 class GCTimer; 86 class OopStorage; 87 88 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 89 // They are all "well-known", in the sense that no class loader is allowed 90 // to provide a different definition. 91 // 92 // These klasses must all have names defined in vmSymbols. 93 94 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 95 96 // Each well-known class has a short klass name (like object_klass), 97 // a vmSymbol name (like java_lang_Object), and a flag word 98 // that makes some minor distinctions, like whether the klass 99 // is preloaded, optional, release-specific, etc. 100 // The order of these definitions is significant; it is the order in which 101 // preloading is actually performed by initialize_preloaded_classes. 102 103 #define WK_KLASSES_DO(do_klass) \ 104 /* well-known classes */ \ 105 do_klass(Object_klass, java_lang_Object, Pre ) \ 106 do_klass(String_klass, java_lang_String, Pre ) \ 107 do_klass(Class_klass, java_lang_Class, Pre ) \ 108 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 109 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 110 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 111 do_klass(System_klass, java_lang_System, Pre ) \ 112 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 113 do_klass(Error_klass, java_lang_Error, Pre ) \ 114 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 115 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 116 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 117 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 118 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 119 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 120 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \ 121 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 122 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 123 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 124 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 125 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 126 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 127 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 128 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 129 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 130 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 131 \ 132 /* Preload ref klasses and set reference types */ \ 133 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 134 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 135 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 136 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 137 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 138 \ 139 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 140 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 141 do_klass(Properties_klass, java_util_Properties, Pre ) \ 142 do_klass(Module_klass, java_lang_Module, Pre ) \ 143 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 144 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 145 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \ 146 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \ 147 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \ 148 \ 149 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 150 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 151 do_klass(reflect_MagicAccessorImpl_klass, reflect_MagicAccessorImpl, Opt ) \ 152 do_klass(reflect_MethodAccessorImpl_klass, reflect_MethodAccessorImpl, Pre ) \ 153 do_klass(reflect_ConstructorAccessorImpl_klass, reflect_ConstructorAccessorImpl, Pre ) \ 154 do_klass(reflect_DelegatingClassLoader_klass, reflect_DelegatingClassLoader, Opt ) \ 155 do_klass(reflect_ConstantPool_klass, reflect_ConstantPool, Opt ) \ 156 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl, Opt ) \ 157 do_klass(reflect_CallerSensitive_klass, reflect_CallerSensitive, Opt ) \ 158 \ 159 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 160 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \ 161 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \ 162 do_klass(VarHandle_klass, java_lang_invoke_VarHandle, Pre ) \ 163 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \ 164 do_klass(ResolvedMethodName_klass, java_lang_invoke_ResolvedMethodName, Pre ) \ 165 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \ 166 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 167 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \ 168 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \ 169 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \ 170 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \ 171 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \ 172 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \ 173 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \ 174 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 175 \ 176 do_klass(AssertionStatusDirectives_klass, java_lang_AssertionStatusDirectives, Pre ) \ 177 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 178 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 179 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe, Pre ) \ 180 do_klass(module_Modules_klass, jdk_internal_module_Modules, Pre ) \ 181 \ 182 /* support for CDS */ \ 183 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \ 184 do_klass(URL_klass, java_net_URL, Pre ) \ 185 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 186 do_klass(jdk_internal_loader_ClassLoaders_klass, jdk_internal_loader_ClassLoaders, Pre ) \ 187 do_klass(jdk_internal_loader_ClassLoaders_AppClassLoader_klass, jdk_internal_loader_ClassLoaders_AppClassLoader, Pre ) \ 188 do_klass(jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass, jdk_internal_loader_ClassLoaders_PlatformClassLoader, Pre ) \ 189 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 190 \ 191 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 192 \ 193 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 194 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \ 195 \ 196 /* Stack Walking */ \ 197 do_klass(StackWalker_klass, java_lang_StackWalker, Opt ) \ 198 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker, Opt ) \ 199 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo, Opt ) \ 200 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo, Opt ) \ 201 \ 202 /* support for stack dump lock analysis */ \ 203 do_klass(java_util_concurrent_locks_AbstractOwnableSynchronizer_klass, java_util_concurrent_locks_AbstractOwnableSynchronizer, Pre ) \ 204 \ 205 /* Preload boxing klasses */ \ 206 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 207 do_klass(Character_klass, java_lang_Character, Pre ) \ 208 do_klass(Float_klass, java_lang_Float, Pre ) \ 209 do_klass(Double_klass, java_lang_Double, Pre ) \ 210 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 211 do_klass(Short_klass, java_lang_Short, Pre ) \ 212 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 213 do_klass(Long_klass, java_lang_Long, Pre ) \ 214 \ 215 /* JVMCI classes. These are loaded on-demand. */ \ 216 JVMCI_WK_KLASSES_DO(do_klass) \ 217 \ 218 /*end*/ 219 220 221 class SystemDictionary : AllStatic { 222 friend class VMStructs; 223 friend class SystemDictionaryHandles; 224 225 public: 226 enum WKID { 227 NO_WKID = 0, 228 229 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 230 WK_KLASSES_DO(WK_KLASS_ENUM) 231 #undef WK_KLASS_ENUM 232 233 WKID_LIMIT, 234 235 #if INCLUDE_JVMCI 236 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(JVMCI_klass), 237 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass), 238 #endif 239 240 FIRST_WKID = NO_WKID + 1 241 }; 242 243 enum InitOption { 244 Pre, // preloaded; error if not present 245 246 // Order is significant. Options before this point require resolve_or_fail. 247 // Options after this point will use resolve_or_null instead. 248 249 Opt, // preload tried; NULL if not present 250 #if INCLUDE_JVMCI 251 Jvmci, // preload tried; error if not present if JVMCI enabled 252 #endif 253 OPTION_LIMIT, 254 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 255 }; 256 257 258 // Returns a class with a given class name and class loader. Loads the 259 // class if needed. If not found a NoClassDefFoundError or a 260 // ClassNotFoundException is thrown, depending on the value on the 261 // throw_error flag. For most uses the throw_error argument should be set 262 // to true. 263 264 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 265 // Convenient call for null loader and protection domain. 266 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 267 protected: 268 // handle error translation for resolve_or_null results 269 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, TRAPS); 270 271 public: 272 273 // Returns a class with a given class name and class loader. 274 // Loads the class if needed. If not found NULL is returned. 275 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 276 // Version with null loader and protection domain 277 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 278 279 // Resolve a superclass or superinterface. Called from ClassFileParser, 280 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 281 // "child_name" is the class whose super class or interface is being resolved. 282 static Klass* resolve_super_or_fail(Symbol* child_name, 283 Symbol* class_name, 284 Handle class_loader, 285 Handle protection_domain, 286 bool is_superclass, 287 TRAPS); 288 289 // Parse new stream. This won't update the dictionary or 290 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 291 // Also used by Unsafe_DefineAnonymousClass 292 static InstanceKlass* parse_stream(Symbol* class_name, 293 Handle class_loader, 294 Handle protection_domain, 295 ClassFileStream* st, 296 TRAPS) { 297 return parse_stream(class_name, 298 class_loader, 299 protection_domain, 300 st, 301 NULL, // host klass 302 NULL, // cp_patches 303 THREAD); 304 } 305 static InstanceKlass* parse_stream(Symbol* class_name, 306 Handle class_loader, 307 Handle protection_domain, 308 ClassFileStream* st, 309 const InstanceKlass* host_klass, 310 GrowableArray<Handle>* cp_patches, 311 TRAPS); 312 313 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 314 static InstanceKlass* resolve_from_stream(Symbol* class_name, 315 Handle class_loader, 316 Handle protection_domain, 317 ClassFileStream* st, 318 TRAPS); 319 320 // Lookup an already loaded class. If not found NULL is returned. 321 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 322 323 // Lookup an already loaded instance or array class. 324 // Do not make any queries to class loaders; consult only the cache. 325 // If not found NULL is returned. 326 static Klass* find_instance_or_array_klass(Symbol* class_name, 327 Handle class_loader, 328 Handle protection_domain, 329 TRAPS); 330 331 // Lookup an instance or array class that has already been loaded 332 // either into the given class loader, or else into another class 333 // loader that is constrained (via loader constraints) to produce 334 // a consistent class. Do not take protection domains into account. 335 // Do not make any queries to class loaders; consult only the cache. 336 // Return NULL if the class is not found. 337 // 338 // This function is a strict superset of find_instance_or_array_klass. 339 // This function (the unchecked version) makes a conservative prediction 340 // of the result of the checked version, assuming successful lookup. 341 // If both functions return non-null, they must return the same value. 342 // Also, the unchecked version may sometimes be non-null where the 343 // checked version is null. This can occur in several ways: 344 // 1. No query has yet been made to the class loader. 345 // 2. The class loader was queried, but chose not to delegate. 346 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 347 // 4. Loading was attempted, but there was a linkage error of some sort. 348 // In all of these cases, the loader constraints on this type are 349 // satisfied, and it is safe for classes in the given class loader 350 // to manipulate strongly-typed values of the found class, subject 351 // to local linkage and access checks. 352 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 353 Handle class_loader, 354 TRAPS); 355 356 static void classes_do(MetaspaceClosure* it); 357 // Iterate over all methods in all klasses 358 359 static void methods_do(void f(Method*)); 360 361 // Garbage collection support 362 363 // Unload (that is, break root links to) all unmarked classes and 364 // loaders. Returns "true" iff something was unloaded. 365 static bool do_unloading(GCTimer* gc_timer, 366 bool do_cleaning = true); 367 368 // Used by DumpSharedSpaces only to remove classes that failed verification 369 static void remove_classes_in_error_state(); 370 371 static int calculate_systemdictionary_size(int loadedclasses); 372 373 // Applies "f->do_oop" to all root oops in the system dictionary. 374 static void oops_do(OopClosure* f); 375 376 // System loader lock 377 static oop system_loader_lock() { return _system_loader_lock_obj; } 378 379 public: 380 // Sharing support. 381 static void reorder_dictionary_for_sharing() NOT_CDS_RETURN; 382 static void combine_shared_dictionaries(); 383 static size_t count_bytes_for_buckets(); 384 static size_t count_bytes_for_table(); 385 static void copy_buckets(char* top, char* end); 386 static void copy_table(char* top, char* end); 387 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 388 int number_of_entries); 389 // Printing 390 static void print() { return print_on(tty); } 391 static void print_on(outputStream* st); 392 static void print_shared(outputStream* st); 393 static void dump(outputStream* st, bool verbose); 394 395 // Monotonically increasing counter which grows as classes are 396 // loaded or modifications such as hot-swapping or setting/removing 397 // of breakpoints are performed 398 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 399 // Needed by evolution and breakpoint code 400 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 401 402 // Verification 403 static void verify(); 404 405 // Initialization 406 static void initialize(TRAPS); 407 408 // Checked fast access to commonly used classes - mostly preloaded 409 static InstanceKlass* check_klass(InstanceKlass* k) { 410 assert(k != NULL, "klass not loaded"); 411 return k; 412 } 413 414 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); } 415 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; } 416 417 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; }) 418 419 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 420 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 421 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 422 int limit = (int)end_id + 1; 423 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 424 } 425 426 public: 427 #define WK_KLASS_DECLARE(name, symbol, option) \ 428 static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 429 static InstanceKlass** name##_addr() { \ 430 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 431 } 432 WK_KLASSES_DO(WK_KLASS_DECLARE); 433 #undef WK_KLASS_DECLARE 434 435 static InstanceKlass* well_known_klass(WKID id) { 436 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 437 return _well_known_klasses[id]; 438 } 439 440 static InstanceKlass** well_known_klass_addr(WKID id) { 441 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 442 return &_well_known_klasses[id]; 443 } 444 static void well_known_klasses_do(MetaspaceClosure* it); 445 446 // Local definition for direct access to the private array: 447 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 448 449 static InstanceKlass* box_klass(BasicType t) { 450 assert((uint)t < T_VOID+1, "range check"); 451 return check_klass(_box_klasses[t]); 452 } 453 static BasicType box_klass_type(Klass* k); // inverse of box_klass 454 455 protected: 456 // Returns the class loader data to be used when looking up/updating the 457 // system dictionary. 458 static ClassLoaderData *class_loader_data(Handle class_loader) { 459 return ClassLoaderData::class_loader_data(class_loader()); 460 } 461 462 public: 463 // Tells whether ClassLoader.checkPackageAccess is present 464 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 465 466 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 467 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 468 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 469 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 470 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 471 472 // Returns java system loader 473 static oop java_system_loader(); 474 475 // Returns java platform loader 476 static oop java_platform_loader(); 477 478 // Compute the java system and platform loaders 479 static void compute_java_loaders(TRAPS); 480 481 // Register a new class loader 482 static ClassLoaderData* register_loader(Handle class_loader); 483 protected: 484 // Mirrors for primitive classes (created eagerly) 485 static oop check_mirror(oop m) { 486 assert(m != NULL, "mirror not initialized"); 487 return m; 488 } 489 490 public: 491 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 492 493 // Check class loader constraints 494 static bool add_loader_constraint(Symbol* name, Handle loader1, 495 Handle loader2, TRAPS); 496 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 497 Handle loader2, bool is_method, TRAPS); 498 499 // JSR 292 500 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 501 // (asks Java to compute it if necessary, except in a compiler thread) 502 static methodHandle find_method_handle_invoker(Klass* klass, 503 Symbol* name, 504 Symbol* signature, 505 Klass* accessing_klass, 506 Handle *appendix_result, 507 Handle *method_type_result, 508 TRAPS); 509 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 510 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 511 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 512 Symbol* signature, 513 TRAPS); 514 515 // compute java_mirror (java.lang.Class instance) for a type ("I", "[[B", "LFoo;", etc.) 516 // Either the accessing_klass or the CL/PD can be non-null, but not both. 517 static Handle find_java_mirror_for_type(Symbol* signature, 518 Klass* accessing_klass, 519 Handle class_loader, 520 Handle protection_domain, 521 SignatureStream::FailureMode failure_mode, 522 TRAPS); 523 static Handle find_java_mirror_for_type(Symbol* signature, 524 Klass* accessing_klass, 525 SignatureStream::FailureMode failure_mode, 526 TRAPS) { 527 // callee will fill in CL/PD from AK, if they are needed 528 return find_java_mirror_for_type(signature, accessing_klass, Handle(), Handle(), 529 failure_mode, THREAD); 530 } 531 532 533 // fast short-cut for the one-character case: 534 static oop find_java_mirror_for_type(char signature_char); 535 536 // find a java.lang.invoke.MethodType object for a given signature 537 // (asks Java to compute it if necessary, except in a compiler thread) 538 static Handle find_method_handle_type(Symbol* signature, 539 Klass* accessing_klass, 540 TRAPS); 541 542 // find a java.lang.Class object for a given signature 543 static Handle find_field_handle_type(Symbol* signature, 544 Klass* accessing_klass, 545 TRAPS); 546 547 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 548 static Handle link_method_handle_constant(Klass* caller, 549 int ref_kind, //e.g., JVM_REF_invokeVirtual 550 Klass* callee, 551 Symbol* name, 552 Symbol* signature, 553 TRAPS); 554 555 // ask Java to compute a constant by invoking a BSM given a Dynamic_info CP entry 556 static Handle link_dynamic_constant(Klass* caller, 557 int condy_index, 558 Handle bootstrap_specifier, 559 Symbol* name, 560 Symbol* type, 561 TRAPS); 562 563 // ask Java to create a dynamic call site, while linking an invokedynamic op 564 static methodHandle find_dynamic_call_site_invoker(Klass* caller, 565 int indy_index, 566 Handle bootstrap_method, 567 Symbol* name, 568 Symbol* type, 569 Handle *appendix_result, 570 Handle *method_type_result, 571 TRAPS); 572 573 // Record the error when the first attempt to resolve a reference from a constant 574 // pool entry to a class fails. 575 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error, 576 Symbol* message); 577 static void delete_resolution_error(ConstantPool* pool); 578 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which, 579 Symbol** message); 580 581 582 static ProtectionDomainCacheEntry* cache_get(Handle protection_domain); 583 584 protected: 585 586 enum Constants { 587 _loader_constraint_size = 107, // number of entries in constraint table 588 _resolution_error_size = 107, // number of entries in resolution error table 589 _invoke_method_size = 139, // number of entries in invoke method table 590 _shared_dictionary_size = 1009, // number of entries in shared dictionary 591 _placeholder_table_size = 1009 // number of entries in hash table for placeholders 592 }; 593 594 595 // Static tables owned by the SystemDictionary 596 597 // Hashtable holding placeholders for classes being loaded. 598 static PlaceholderTable* _placeholders; 599 600 // Hashtable holding classes from the shared archive. 601 static Dictionary* _shared_dictionary; 602 603 // Monotonically increasing counter which grows with 604 // loading classes as well as hot-swapping and breakpoint setting 605 // and removal. 606 static int _number_of_modifications; 607 608 // Lock object for system class loader 609 static oop _system_loader_lock_obj; 610 611 // Constraints on class loaders 612 static LoaderConstraintTable* _loader_constraints; 613 614 // Resolution errors 615 static ResolutionErrorTable* _resolution_errors; 616 617 // Invoke methods (JSR 292) 618 static SymbolPropertyTable* _invoke_method_table; 619 620 // ProtectionDomain cache 621 static ProtectionDomainCacheTable* _pd_cache_table; 622 623 // VM weak OopStorage object. 624 static OopStorage* _vm_weak_oop_storage; 625 626 protected: 627 static void validate_protection_domain(InstanceKlass* klass, 628 Handle class_loader, 629 Handle protection_domain, TRAPS); 630 631 friend class VM_PopulateDumpSharedSpace; 632 friend class TraversePlaceholdersClosure; 633 static Dictionary* shared_dictionary() { return _shared_dictionary; } 634 static PlaceholderTable* placeholders() { return _placeholders; } 635 static LoaderConstraintTable* constraints() { return _loader_constraints; } 636 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 637 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 638 639 // Basic loading operations 640 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 641 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 642 static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 643 // Wait on SystemDictionary_lock; unlocks lockObject before 644 // waiting; relocks lockObject with correct recursion count 645 // after waiting, but before reentering SystemDictionary_lock 646 // to preserve lock order semantics. 647 static void double_lock_wait(Handle lockObject, TRAPS); 648 static void define_instance_class(InstanceKlass* k, TRAPS); 649 static InstanceKlass* find_or_define_instance_class(Symbol* class_name, 650 Handle class_loader, 651 InstanceKlass* k, TRAPS); 652 static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik, 653 Handle class_loader, TRAPS); 654 static InstanceKlass* load_shared_class(InstanceKlass* ik, 655 Handle class_loader, 656 Handle protection_domain, 657 TRAPS); 658 static InstanceKlass* load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 659 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 660 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 661 static bool is_parallelCapable(Handle class_loader); 662 static bool is_parallelDefine(Handle class_loader); 663 664 public: 665 static InstanceKlass* load_shared_class(Symbol* class_name, 666 Handle class_loader, 667 TRAPS); 668 static bool is_system_class_loader(oop class_loader); 669 static bool is_platform_class_loader(oop class_loader); 670 static void clear_invoke_method_table(); 671 672 // Returns TRUE if the method is a non-public member of class java.lang.Object. 673 static bool is_nonpublic_Object_method(Method* m) { 674 assert(m != NULL, "Unexpected NULL Method*"); 675 return !m->is_public() && m->method_holder() == SystemDictionary::Object_klass(); 676 } 677 678 static void initialize_oop_storage(); 679 static OopStorage* vm_weak_oop_storage(); 680 681 protected: 682 static InstanceKlass* find_shared_class(Symbol* class_name); 683 684 // Setup link to hierarchy 685 static void add_to_hierarchy(InstanceKlass* k, TRAPS); 686 687 // Basic find on loaded classes 688 static InstanceKlass* find_class(unsigned int hash, 689 Symbol* name, Dictionary* dictionary); 690 static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 691 692 // Basic find on classes in the midst of being loaded 693 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 694 695 // Add a placeholder for a class being loaded 696 static void add_placeholder(int index, 697 Symbol* class_name, 698 ClassLoaderData* loader_data); 699 static void remove_placeholder(int index, 700 Symbol* class_name, 701 ClassLoaderData* loader_data); 702 703 // Performs cleanups after resolve_super_or_fail. This typically needs 704 // to be called on failure. 705 // Won't throw, but can block. 706 static void resolution_cleanups(Symbol* class_name, 707 ClassLoaderData* loader_data, 708 TRAPS); 709 710 // Initialization 711 static void initialize_preloaded_classes(TRAPS); 712 713 // Class loader constraints 714 static void check_constraints(unsigned int hash, 715 InstanceKlass* k, Handle loader, 716 bool defining, TRAPS); 717 static void update_dictionary(unsigned int d_hash, 718 int p_index, unsigned int p_hash, 719 InstanceKlass* k, Handle loader, 720 TRAPS); 721 722 // Variables holding commonly used klasses (preloaded) 723 static InstanceKlass* _well_known_klasses[]; 724 725 // table of box klasses (int_klass, etc.) 726 static InstanceKlass* _box_klasses[T_VOID+1]; 727 728 private: 729 static oop _java_system_loader; 730 static oop _java_platform_loader; 731 732 static bool _has_checkPackageAccess; 733 }; 734 735 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP